Clutch for a stretching mechanism is a spinning or twisting machine

ABSTRACT

A clutch for a stretching mechanism in a spinning or twisting machine in which a drivable stretching roller is connected to a co-axial drive shaft by a clutch which can be disengaged by a thread monitor with the aid of a stop motion in the event of the thread breaking, wherein the clutch comprises two halves one of which carries coupling elements, such as spring-loaded balls, which can engage corresponding catch bores in the other halfclutch, and a rotatable ratchet disc with tapered apertures through the larger ends of which the coupling elments can project is disposed between the two half-clutches, the ratchet disc being arranged to be braked by the stop motion on breakage of the thread so as to force the coupling elements out of engagement with the catch bores and thereby to disengage the clutch.

United States Patent [191 Gardella 1 CLUTCH FOR A STRETCHING MECHANISMIS A SPKNNING OR TWISTING MACHINE [76] Inventor: Adriano Gardella, 248,via a1 Capo di Santu Chiara, Genoa, Italy 16146 [22] Filed: June 14,1972 [21] Appl. No.: 262,698

[30] Foreign Application Priority Data June 21,1971 Italy 12763/71 [52]11.5. C1 57/83, 192/24, 192/45 [51] Int. Cl. B0111 13/16, DOlh 13/18[58] Field of Search 57/78, 83, 80, 79, 84-87;

[56] References Cited UNITED STATES PATENTS 2/1929 Schloz ..192/251/1943 Eason....

[ .lune 11, 1974 2,685,948 8/1954 Freeman et a1 192/25 2,807,131 9/1957Bade 3,327,464 6/1967 HalleuX 3,385,044 5/1968 Anderson et a1. 57/83 XPrimary Examiner-John Petrakes Attorney, Agent, or Firm-Larson, Taylor &Hinds 5 7] ABSTRACT A clutch for a stretching mechanism in a spinning ortwisting machine in which a drivable stretching roller is connected to aco-axial drive shaft by a clutch which can be disengaged by a threadmonitor with the aid of a stop motion in the event of the threadbreaking, wherein the clutch comprises two halves one of which carriescoupling elements, such as spring-loaded balls, which can engagecorresponding catch bores in the other half-clutch, and a rotatableratchet disc with tapered apertures through the larger ends of which thecoupling elments can project is disposed between the two half-clutches,the ratchet disc being arranged to be braked by the stop motion onbreakage of the thread so as to force the coupling elements out ofengagement with the catch bores and thereby to disengage the clutch.

5 Claims, 5 Drawing Figures BACKGROUND OF THE INVENTION The inventionrelates to a clutch for stretching mech anisms in spinning or twistingmachines, in which a drivable stretching roller mounted for freerotation is connected to a drive shaft disposed coaxially to it by aclutch adapted to be disconnected by a thread monitor with the aid of astop motion in the event of a thread breaking.

In spinning or twisting machines having a plurality of juxtaposedspindles the stretching mechanisms associated with the individualspindles are driven by a common drive shaft which is connected to aroller in each stretching mechanism, for example a roller of the pair offeed rollers. This driven stretching roller in turn drives the otherrollers or other parts, for example the belt or belts of the respectivestretching mechanism. In the event of a thread breaking on one spindle,it is necessary to stop only the associated stretching mechanism,thereby interrupting the feeding of the sliver, while the spinning ortwisting operation is continued with the other spindles. For thispurpose the drivable roller of each stretching mechanism is connected tothe drive shaft disposed coaxially to it by a clutch adapted to bedisengaged by a thread monitor with the aid of a stop motion in theevent of a thread breaking.

The problem underlying the invention consists in providing a clutch ofthis kind which has a particularly simple, space-saving, and economicalconstruction and which in conjunction with ease of operation and greatoperational reliability is adapted to be automatically disengaged notonly on the breaking of a thread but also in the event of disturbances,particularly the obstruction and braking of the running of thestretching mechanism.

SUMMARY In a clutch of the type described above this problem is solvedaccording to the invention through the fact that a half-clutchsecured torotate with the drive shaft and a half-clutch lying opposite thereto andsecured to rotate with the drivable stretching roller are adapted to beconnected together for simultaneous rotation by coupling elements whichare movably mounted, axially parallel to the drive shaft or to thestretching roller, in one half-clutch and partly engage by theirhemispherical ends, under the action of associated engaging springs, incorresponding catch bores in the other halfclutch, and that between thetwo half-clutches a ratchet disc, which is coaxial thereto and which isadapted to, be'braked or locked by the stop motion of the spinning ortwisting machine in the event of a thread breaking, is mounted for freerotation and is provided with In this construction of a clutch forstretching mechanisms in spinning or twisting machines the hemisphericalends of the coupling elements of one half-clutch partly engage, in theoperative position, through the wider end portion of each curvedaperture in the ratchet disc, so as to penetrate into a correspondingcatch bore in the other half-clutch. The clutch is consequentlyengagedand the drivable stretching roller is driven rotationally by the driveshaft, while the ratchet disc disposed between the two half-clutchesalso rotates at the same speed. In the event of a thread breaking, theratchet disc is braked or locked by the thread monitor with the aid ofthe stop motion. Consequently, the coupling elements, which at firstcontinue to rotate together with the stretching roller and the driveshaft, move towards the narrower end of the respective curved aperturesof the ratchet disc and are thereby pressed out of the correspondingcatch bores in the other half-clutch against the force .of theirrespective engaging springs. The clutch is consequently disengaged andthe rotational connection between the stretching roller and the driveshaft interrupted. After the thread breakage has been mended, it ismerely necessary to release the ratchet disc again. In consequence of apartial rotation in relation to the half-clutch provided with thecoupling elements it then automatically resumes within a very short timeits operating position in which the coupling elements come to lie in theregion of the wider end portion of each aperture in the ratchet disc, sothat their hemispherical ends can pass through these apertures in theratchet disc and engage tion of the running of the stretching mechanism,that is in respective catch bores in the other half-clutch under theaction of the associated engaging springs. The clutch is therebyrc-engaged.

In the event of disturbances, particularly the obstructo say if thehalf-clutch associated with the drivable stretching roller is heavilybraked or stopped, the cou- BRIEF DESCRIPTION OF THE DRAWINGS In theaccompanying drawings: FIG. 1 shows the pair of feed rollers of astretching mechanism, equipped with the clutch according to theinvention, for spinning or twisting machines, in side elecurvedapertures which are angularly spaced around penetration of thehemispherical ends of the coupling elements and the engagement of eachof them in a catch bore to a minimum width preventing the engagement ofthe hemispherical ends of the coupling elements in the catch bores.

vation,

FIG. 2 is a plan view of the pair of feed rollers shown in FIG. 1, on asmaller scale,

FIG. 3 is a longitudinal section through the drivable feed roller,connected by a clutch to the drive shaft, in the stretching mechanismshown in FIGS. 1 and 2,

FIG. 4 is a side elevation of the clutch viewed in the direction IV-IVin FIG. 3, and

FIG. 5 is a cross-section through the clutch on the line VV in FIG. 3.

DETAILED DESCRIPTION OF THEINVENTION FIGS. 1 and 2 of the drawings showthe pair of feed rollers 1,2 of a stretching mechanism for spinning ortwisting machines. The drivable feed roller 1 is freely rotatable on adrive shaft 3, which is common to all the stretching mechanisms of thespinning or twisting machine, but can be connected to said shaft by aclutch which will be described more fully below. The other feed rollermay be in the form of a pressure roller. The drivable feed roller 1 isprovided at one end with a coupling flange 4, which on its periphery isformed as a gear 5. This gear 5 meshes with a gear 6 which isrotationally fastened to the top guide roller 7 of a belt 8. Belt 8 isthe belt of the tape stretching mechanism to which the sliver referredto hereinabove is fed. The drive for the belt 8 is therefore taken fromthe drive shaft 3 through the feed roller 1 and the pair of gears 5, 6.The belt 8 co-operates with pivotally mounted guide rollers 9.

In the embodiment illustrated the drivable feed roller 1 is mounted forfree rotation on a bearing bush 10 which is mounted on the drive shaft3, to which the bush is secured against relative rotation by a threadedpin 11, as can be seen particularly in FIG. 3. On the opposite side tothat where the coupling flange 4 of the feed roller 1 is disposed thebearing bush 10 has a stop flange 12, which prevents axial displacementof the feed roller 1.

The clutch between the drivable feed roller and the drive shaft 3consists of the aforesaid coupling flange 4 of the feed roller 1' and acoupling flange 14' mounted opposite the flange 4 on the bearing bush 10and rotationally fastened to the bearing bush 10 or to the drive shaft 3by threaded pins 13, as can be seen particularly in FIGS. 2 to 5. In thecoupling flange 4 of the feed roller 1 there are provided blind bores 15which are parallel to the axis and in each of which there is disposed alongitudinally slidable coupling ball 17 pressed by an engaging spring16 outwards against the coupling flange 14 of the drive shaft 3. Part ofthe half of each coupling ball 17 which projects out of the respectivereceiving bore can engage in a corresponding catch bore 18 provided inthe coupling flange 14 of the drive shaft 3.

Between the two coupling flanges 4, 14 a relatively thin ratchet disc 19is mounted for free rotation on the bearing bush 10. This ratchet disc19 has curved apertures 20 which are disposed on the pitch circle of thecoupling balls 17 or of the catch bores 18 and are angularly offset inrelation to one another with the same spacing as the coupling balls 17or catch balls 18, as i]- lustrated particularly in FIG. 5. Eachaperture 20 has a width which decreases progressively in the directionof rotation F of the drive shaft 3. The wide end of each aperture 20 ismade so wide and is so shaped that a coupling ball 17 can projectthrough the wider end portion of the aperture 20 and engage to thedesired extent in a catch bore 18. The other, narrow end of eachaperture 20 of the ratchet disc 19 has on the other hand so slight awidth that a coupling ball 17 cannot pass through this narrower endportion of the aperture 20 to engage in a catch bore 18.

On its periphery the ratchet disc 19 is provided with projecting teeth119, which cooperates with a pawl 21, as illustrated particularly'inFIG. 1. This pawl 21 is operated by a' rocking lever 22 in the stopmotion (not shown) which is known per se and which responds to threadbreakages in the spinning or twisting machine.

23 and 24 denote lubricant'passages for lubricating the sliding surfacesbetween the feed roller 1 and the bearing bush 10.

In the operative position of the clutch the pawl 21 assumes the releasedposition shown in FIG. 1, in which the ratchet disc can turn unhindered.The coupling balls 17 of the coupling flange 4 connected to the feedroller 1 thus engage through the wider end portion of the apertures 20in the ratchet disc 19 and in respective catch bores 18 in the couplingflange 4l'provided with the drive shaft 3, as illustrated particularlyin FIGS. 3 and 5. The coupling flanges 4, 14 are consequently coupledtogether, that is to say the clutch is engaged and the drivable feedroller 1 of the stretching mechanism is rotationally driven by the driveshaft 3. The ratchet disc 19 disposed between the coupling flanges 41,14 is likewise rotated.

When the thread monitor (not shown), which is known per se and is partof the stop motion, detects a thread break, for example between thestretching mechanism and the spinning or twisting spindle following it,the lever 22 of the stop motion is rocked to the left in FIG. 1 andbrings the pawl 21 into engagement with the teeth 119 of the ratchetdisc 19. The ratchet disc 19 is thereby held fast. The coupling balls17, which at first continue to turn in the direction of rota tion F inFIG. 5 together with the feed roller 1 and the drive shaft 3,consequently move towards the narrower end of the respective curvedapertures 20 in the stationary ratchet disc 19 and are consequentlypressed out of the corresponding clutch bores 18 in the coupling flange14 connected to the drive shaft 3, against the force of the appertainingengaging springs 16. The clutch is thereby disengaged, that is to saythe rotational connection between the two coupling flanges 4, 14 andconsequently between the feed-roller land the drive shaft 3 isinterrupted. The feed roller 1 and the belt 8 of the stretchingmechanism are stopped, while the drive shaft 3 together with the bearingbush 10 and resumes within a very short time the operating positionshown in FIG. 5, in which the coupling balls 17 of the coupling flange 4connected to the feed roller 1 come to lie in the wider end region ofthe apertures 20 of the ratchet disc 19 and engage through the apertures20, under the action of the appertaining engaging springs 16, into therespective catch bores 18 in the coupling flange 14 connected to thedrive shaft 3, as illustrated particularly in FIG. 1. The clutch isthereby re-engaged and the feed roller is again coupled to the driveshaft 3.'

In the event of obstruction to the running of the stretching mechanism,for example when the rotation of the feed roller 1 is obstructed orgreatly braked by disturbances of any kind, the clutch described acts asan automatic overload or torque-limiting clutch. When a predeterminedtorque is exceeded, the coupling balls 17, which together with thecoupling flange 4 of the feed roller 1 are braked in their rotationalmovement or held fast, are in fact pressed, against the force of theappertaining engaging springs 16 at the wider edge of the apertures 20,out of the corresponding catch bores 18 in the coupling flange providedon the drive shaft 3 and rotating in the direction of rotation F,whereby the clutch slips and the rotational connection between the 5feed roller 1 and the drive shaft 3 is automatically disengaged.

The invention is naturally not restricted to the embodiment illustrated,but within the framework of the general principle of the invention anumber of different solutions, which differ particularly in respect ofconstruction, are possible. Thus, for example the coupling balls 17 maybe mounted in the coupling flange 14 joined to the drive shaft 3, andthe corresponding catch bores 18 provided in the coupling flange 4connected to the feed roller 1. In addition, the clutch may be disposedbetween any other roller in the stretching mechanism and the respectivedrive shaft. Instead of the coupling balls '17 it is also possible touse cylindrical coupling elements which are axially slidable in thereceiving bores and of which the outer end, directed towards the otherhalf-clutch andpartly engaging in the catch bores 18, is madehemispherical. On the other hand, all the features which can be seenfrom the drawing and description, including constructional details, mayalso be integral parts of the invention in any desired combination.

I claim:

1. A clutch device for a stretching mechanism in a spinning or twistingmachine including a stop motion mechanism actuated by a thread monitorin the event of a thread breaking, said clutch device comprising astretching roller mounted for free rotation,

a drive shaft coaxial with said roller,

a clutch, which is disengaged responsive to actuation of the stop motionmechanism by the thread monitor, for coupling said drive shaft to saidstretching roller, said clutch comprising a first clutch member mountedfor rotation with said shaft, a second clutch member disposed oppositesaid first clutch member and rotatable with said stretching roller, aplurality of movable coupling elements, mounted in one of said clutchmembers for axial movement parallel to the longitudinal axis of saidshaft, for coupling said first clutch member to said second clutchmember, said elements including hemispherical ends and the other of saidclutch member including a corresponding plurality of catch bores inwhich said hemispherical ends are received, a corresponding plurality ofsprings for urging the hemispherical ends of said coupling elements intoengagementin said catch bores, and a ratchet disc, disposed between saidclutch members coaxial therewith and mounted for free rotation, which isbraked responsive to actuation of the stop motion mechanism by thethread monitor. said ratchet disc including a corresponding plurality ofcurved apertures therein angularly spaced about the circumference of acircle which is in registry with said coupling elements and said catchbores, said apertures having a width which progressively decreases inthe direction of rotation of said drive shaft between a maximum widthwhich permits the hemispherical ends of said coupling elements to atleast partially penetrate said apertures so as to engage in said catchbores to a minimum width which prevents said coupling elements fromengaging in said catch bores.

2. A clutch device as claimed in claim lwherein said stretching rollerincludes a flange which forms said first clutch member and wherein saiddrive shaft includes a coupling flange which forms said second clutchmem her.

3. A clutch device as claimed in claim 2 wherein said stretching rolleris mounted for rotation on a bearing bush which is secured to said driveshaft to prevent rel ative movement therebetween, said coupling flangebeing affixed to said bush.

4. A clutch according to claim 1, wherein the coupling elements are inthe form of balls.

5. A clutch according to claim 1, wherein the ratchet disc is providedon its periphery with teeth which cooperate with a pawl adapted to beoperated by the stop

1. A clutch device for a stretching mechanism in a spinning or twistingmachine including a stop motion mechanism actuated by a thread monitorin the event of a thread breaking, said clutch device comprising astretching roller mounted for free rotation, a drive shaft coaxial withsaid roller, a clutch, which is disengaged responsive to actuation ofthe stop motion mechanism by the thread monitor, for coupling said driveshaft to said stretching roller, said clutch comprising a first clutchmember mounted for rotation with said shaft, a second clutch memberdisposed opposite said first clutch member and rotatable with saidstretching roller, a plurality of movable coupling elements, mounted inone of said clutch members for axial movement parallel to thelongitudinal axis of said shaft, for coupling said first clutch memberto said second clutch member, said elements including hemispherical endsand the other of said clutch member including a corresponding pluralityof catch bores in which said hemispherical ends are received, acorresponding plurality of springs for urging the hemispherical ends ofsaid coupling elements into engagement in said catch bores, and aratchet disc, disposed between said clutch members coaxial therewith andmounted for free rotation, which is braked responsive to actuation ofthe stop motion mechanism by the thread monitor, said ratchet discincluding a corresponding plurality of curved apertures thereinangularly spaced about the circumference of a circle which is inregistry with said coupling elements and said catch bores, saidapertures having a width which progressively decreases in the directionof rotation of said drive shaft between a maximum width which permitsthe hemispherical ends of said coupling elements to at least partiallypenetrate said apertures so as to engage in said catch bores to aminimum width which prevents said coupling elements from engaging insaid catch bores.
 2. A clutch device as claimed in claim 1 wherein saidstretching roller includes a flange which forms said first clutch memberand wherein said drive shaft includes a coupling flange which forms saidsecond clutch member.
 3. A clutch device as claimed in claim 2 whereinsaid stretching roller is mounted for rotation on a bearing bush whichis secured to said drive shaft to prevent relative movementtherebetween, said coupling flange being affixed to said bush.
 4. Aclutch according to claim 1, wherein the coupling elements are in theform of balls.
 5. A clutch according to claim 1, wherein the ratchetdisc is provided on its periphery with teeth which cooperate with a pawladapted to be operated by the stop motion.